Status of Exclusion Limits of the KK-parity Non-conserving Resonance Production with Updated 13 TeV LHC

Abstract: Unequal strengths of boundary localised terms lead to non-conservation of the Kaluza--Klein (KK) parity in the 4+1 Universal Extra Dimensional model. Consequently, the first excited KK-partners of Standard Model particles are not stable by any symmetry. In this article, using the latest 13 TeV Large Hadron Collider (LHC) results, we revisit the resonant production of first KK-excitations of the neutral gauge bosons ($G^1$, $B^1$ and $W_3^1$) and their subsequent decay. Specifically, $G^1$ (first KK-excitation of gluon) decays to $t\bar{t}$ pair and $B^1/W_3^1$ (first KK-excitation of electroweak gauge bosons) decay to $\ell^{+}\ell^{-} (\ell \equiv e, \mu)$ pair. We find that the exclusion limits of model parameters obtained at 95\% C.L. from the non-observation of these channels have been shifted towards the lower side of the parameter space compared to our previous analysis at 8 TeV.